1302

class Solution:
    def deepestLeavesSum(self, root: TreeNode) -> int:

        def dfs(node, level):
            if not node:
                return
            elif level == res[0]:
                res[1] += node.val
            elif level > res[0]:
                res[0] = level
                res[1] = node.val
            dfs(node.left, level + 1)
            dfs(node.right, level + 1)

        res = [0, 0]

        dfs(root, 0)

        return res[1]